Ice sheets existed during global heatwave: study

Sheets of ice existed during very hot periods of Earth's history when there were alligators living in the Arctic, a new international study has found.

Ice sheets were present 91 million years ago during one of the hottest periods of life on earth, experts said in a study in the January 11 issue of Science.

That runs counter to the popular notion that glaciers could not have existed in a so-called "super greenhouse" climate, a time when alligators lived in the Arctic and tropical surface ocean temperatures soared to 35-37 degrees Celsius.

US, British, German and Dutch scientists discovered evidence of a 200,000-year era of widespread glaciation during the Turonian 'super-greenhouse' period of the Cretaceous, the research said.

At the time, ice sheets were roughly 60 per cent the size of the current Antarctic ice cap.

The team got their evidence from analyses of sediments deposited in the western Equatorial Atlantic Ocean at that time, they said.